Liquid surface detection devices in the related art include a float arm provided with a float which floats on the liquid surface, a frame for rotatably supporting the float arm, a resistor provided on a substrate which is fixed to the frame, and a contact point which slides on electrodes connected to the resistor in association with the float arm, and detect the position of the liquid surface by detecting electric resistance between the ends of the contact point and the resistor (for example, see Patent Document 1)    Patent Document 1: JP 2004-20538 A